Controlling the default runner¶

In this tutorial we show how to globally controll the default runner. First we import oommfc.

In [1]:

import oommfc

oommfc has a special member oommfc.runner that provides information and control about the default runner and how it is chosen.

The default runner¶

In [2]:

oommfc.runner

Out[2]:

OOMMF runner: UNSET
runner is cached: True

When we import oommfc the OOMMF runner is unset. The runner is chosen automatically when we first ask for oommfc.runner.runner.

In [3]:

# NBVAL_IGNORE_OUTPUT
oommfc.runner.runner

Out[3]:

ExeOOMMFRunner(/opt/miniconda3/envs/ubermag-dev/bin/oommf)

Now we have a default runner. The same does also happen in the background when creating a driver object and calling its drive method without explicitly passing a runner.

A subsequent call to oommfc.runner shows the default runner.

In [4]:

# NBVAL_IGNORE_OUTPUT
oommfc.runner

Out[4]:

OOMMF runner: ExeOOMMFRunner(/opt/miniconda3/envs/ubermag-dev/bin/oommf)
runner is cached: True

We can also see, that the default runner is cached. This is controlled by:

In [5]:

oommfc.runner.cache_runner

Out[5]:

True

Defaults for the different runner types¶

The default values for the envvar OOMMFTCL, the executable oommf, and the docker executable can also be controlled via the runner object. They default to:

In [6]:

oommfc.runner.envvar

Out[6]:

'OOMMFTCL'

In [7]:

oommfc.runner.oommf_exe

Out[7]:

'oommf'

In [8]:

oommfc.runner.docker_exe

Out[8]:

'docker'

Changing the default runner¶

Our current runner is:

In [9]:

# NBVAL_IGNORE_OUTPUT
oommfc.runner

Out[9]:

OOMMF runner: ExeOOMMFRunner(/opt/miniconda3/envs/ubermag-dev/bin/oommf)
runner is cached: True

We can change the default runner by assigning an new OOMMFRunner object to oommfc.runner.runner.

In [10]:

# NBVAL_IGNORE_OUTPUT
try:
    oommfc.runner.runner = oommfc.oommf.TclOOMMFRunner('/path/to/oommf_tcl')
except ValueError as e:
    print('=' * 20)
    print('ValueError:', e)

Running OOMMF (TclOOMMFRunner) [2021/08/12 10:53]... (0.0 s)
OOMMF error:
	command: tclsh /path/to/oommf_tcl boxsi +fg macrospin.mif -exitondone 1
	stdout: 
	stderr: couldn't read file "/path/to/oommf_tcl": no such file or directory



Cannot find OOMMF.
====================
ValueError: new_runner=TclOOMMFRunner(/path/to/oommf_tcl) cannot be used.

In this example we (expectedly) get a ValueError because the path /path/to/oommf_tcl is invalid. The default runner has not been changed:

In [11]:

# NBVAL_IGNORE_OUTPUT
oommfc.runner

Out[11]:

OOMMF runner: ExeOOMMFRunner(/opt/miniconda3/envs/ubermag-dev/bin/oommf)
runner is cached: True

Going back to the default runner¶

We can change the default runner as demonstrated in the previous paragraph. If we later on decide that we want to go back to the default runner choosen by oommfc, we can do so by calling:

In [12]:

oommfc.runner.autoselect_runner()

This call searches for the best available runner (it does not rely on caching) and overwrites the default obtained via oommfc.runner.runner. We still have the same runner, because we actually never sucessfully changed a runner in this tutorial:

In [13]:

# NBVAL_IGNORE_OUTPUT
oommfc.runner

Out[13]:

OOMMF runner: ExeOOMMFRunner(/opt/miniconda3/envs/ubermag-dev/bin/oommf)
runner is cached: True